The proposed meeting to be held at Cold Spring Harbor Laboratory (CSHL) on the Blood-Brain Barrier on December 10th-13th 2014 will assemble leaders in the BBB field to discuss recent discoveries and future directions. This proposal seeks support for the fourth of a biennial series of meetings held at CSHL on the BBB. This meeting has emerged as a premiere scientific conference in the BBB field. In contrast to other meetings focused on the BBB, the CSHL BBB meeting focuses on the molecular and cellular mechanisms of BBB biology as it relates to development, function, and disease. It is emphasizes molecular genetics and model organism approaches to dissecting BBB biology. Topics to be discussed for the 2014 meeting will include: i. BBB Development; ii. The Functional BBB; iii. BBB in a Dish; IV. Molecular BBB Transport; v. The Diseased BBB; VI. Pericytes, Astrocytes and the BBB. Given the recent fundamental discoveries in the BBB field, and the diverse approaches and models currently employed to unravel BBB biology, communication among international researchers is essential to continue to advance research focused on the BBB. Two leading scientists will chair each session and selected speakers primarily include graduate students, postdoctoral fellows and junior faculty. Two special lectures will be presented to provide essential background critical to stimulating discussion between scientists working on related but distinct areas. There will also be two poster sessions where a majority of participants can present their work. The meeting will be of moderate size, as it has grown steadily from its inception in 2008. We expect >120 participants, including a significant number of students and postdoctoral fellows.